1. Field of the Invention
This invention relates to determination of camera motion, and more particularly to determination of camera motion in a three-dimensional imaging system.
2. Description of the Related Art
Three-dimensional image capture has long held promise as a data acquisition technique for a wide range of modeling systems including computer-aided design systems, digital animation systems, medical imaging systems, graphical design and artwork systems, and the like.
One general technique for capturing three-dimensional data reconstructs an aggregate three-dimensional point cloud using sequential images from a moving camera, which raises the complementary problem of determining camera motion from image to image. A common approach to recovery of camera motion for these image sequences employs factorization on established point correspondences between two-dimensional images. However, this technique is computationally intensive because point correspondence must be maintained over a number of sequential images. This raises additional difficulties in real imaging environments where particular points may be obstructed, or fall entirely out of the image plane.
Another general technique for capturing three-dimensional data employs camera hardware that can directly capture a three-dimensional point cloud by triangulating corresponding points in sets of two-dimensional images from a stereoscopic or multi-aperture device. For these three-dimensional cameras, camera motion can be determined using three-dimensional registration of sequential three-dimensional point clouds. However, typical registration techniques such as the iterative closest point (“ICP”) method do not perform well with difficult-to-register surfaces, such as planar regions. Further, iterative solutions are, in general, poorly suited to real-time imaging applications due to the requirement for multiple, successive calculations, frequently with large data sets.
There remains a need for a robust, efficient technique for determining camera motion that is suitable for use in applications such as real time, three-dimensional image capture.